Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Stock-Based Compensation - Summary of Non-Employee RSU Activity (Details)

v3.10.0.1
Stock-Based Compensation Stock-Based Compensation - Summary of Non-Employee RSU Activity (Details) - Restricted Stock Units (RSUs) - shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vested as of December 31 (in shares) 137,000  
Outstanding as of December 31 (in shares) 324,600 231,600
2016 Directors' Plan    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Vested as of December 31 (in shares) 174,442 140,146
Granted (in shares) 67,288 48,722
Outstanding as of December 31 (in shares) 241,730 188,868